Upgrade from v3.5.5 to v4.0.7 Works Perfectly


It’s been a while since I used copter firmware which may be evident from my v3.5.5 to v4.0.7 upgrade. The host was a 250mm quad using a Pixracer flight controller. The upgrade also changed my NutX to ChibiOS.

To my surprise and joy, the upgrade was flawless using Mission Planner v1.3.74 and I didn’t have to change any parameters or recalibrate the ACC or compass. I just took it out in the backyard and it flew perfectly! I thought that I would post my success and give thanks to all the developers for a job well done!

The reason for my upgrade to v4.0.7 was to use my 250mm quad as a host to test a Matek GNSS M9N-5883 module over my existing M8N module that receives from 11 to 16 satellites. Has anyone used this NEO-M9N module? Any comments on the number of satellites received? My 250mm quad has a nice hold in Loiter mode using the current M8N module so I wonder if there is a certain number of satellites received when it is no longer beneficial?


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According to the Matek Tips and Notes section, it says that the NEO-M9N is supported by ArduPilot 4.1 (latest) firmware. According to the Copter Release Notes, I am ok using v4.0.7 stable. Thoughts?

I have heard that you can push the update rate from 5Hz to maybe 8-10Hz on the NEO-M9N but not to 25Hz. Does the update rate really improve the position holding accuracy or is it playing with the possibility of GPS glitches? In other words, is the increase in # of satellites at a 5Hz update rate the biggest bang with the NEO-M9N?


I swapped out my M8N for the newer Matek M9N-5883 GPS/Compass module. It comes with a 6-pin JST-GH cable that is compatible with the Pixracer.

The weather wasn’t great in my backyard but I still got 19 satellites compared to my M8N’s 11 satellites the day before. I will test it again in an open field but I already saw a nice improvement. The 5883 compass setup worked well and it calibrated nicely using the Onboard Mag Calibration feature in Mission Planner v1.3.74.

My GPS_RATE_MS remains at 200 or 5Hz so that I can receive more than 16 satellites. I did a QLOITER test in my backyard and it seemed to work great. So far, so good with the M9N. The small 25mm patch antenna is fine for my 250mm quad but I will look for a larger M9N module for my larger VTOL models.

great news Greg now back to some nice relaxed flying fun and enjoy

Wow Great news as I am getting ready to do much the same only from 3.6. Moved 2 years ago and havn’t flow one machine since then, so I hope to try ther same. Fantastind software, thanks to all the delopoeers as well.